Traditional watermark technologies typically provide security mechanisms to prevent counterfeit items. The watermarks, which can be both visible and invisible, are typically placed on source documents and can function to provide authorship and rights protection, veracity, and a tamperproof mechanism. One area in which watermarks have been used is with digital content that is accessible through the Internet. In particular, watermarks have been used to control how digital content (e.g., digital libraries, on-line newspapers, magazines, scientific journals, encyclopedias, personal blogs, stores, advertisements, etc.) is distributed or re-used. Natural language (NL) watermarking is one type of watermark technology that has been used to control how digital content is distributed or re-used. NL watermarking generally seeks to embed information in a text document by manipulating the semantic and/or syntactic structure of sentences. NL watermarking is different from text watermarking, which typically modifies the appearance of text formats or fonts such as for example, modifying inter-word and inter-letter spacing in text.